Using player variables - AWS Elemental MediaTailor

Using player variables

To configure AWS Elemental MediaTailor to send data received from the player to the ADS, in the template ADS URL, specify player_params.<query_parameter_name> variables. For example, if the player sends a query parameter named user_id in its request to MediaTailor, to pass that data in the ADS request, include [player_params.user_id] in the ADS URL configuration.

This allows you to control the query parameters that are included in the ADS request. Typically, you add a special query parameter that the ADS recognizes to the ADS request URL and provide key-value pairs as the value of the parameter.

The examples used in the following procedure use the following key-value pairs:

  • param1 with a value of value1:

  • param2 with a value of value2:

To add query parameters as key-value pairs

  1. In AWS Elemental MediaTailor, configure the ADS request template URL to reference the parameters. The following URL shows the inclusion of the example parameters:[player_params.param1]&param2=[player_params.param2]
  2. (Optional) For server-side ad-tracking reporting, URL-encode the key-value pairs on the player. When MediaTailor receives the session initialization request, it URL-decodes the values once before substituting them into the ADS request URL.


    If your ADS requires a URL-encoded value, URL-encode the value twice on the player. This way, the decoding done by MediaTailor results in a once-encoded value for the ADS.

    For example, if the decoded representation of the values sent to the ADS is param1=value1:&param2=value2:, then the URL-encoded representation is param1=value1%3A&param2=value2%3A.

  3. In the session initialization call from the player, pass the key-value pairs to MediaTailor as the value of a single query parameter. The following example calls provide the example key-value pairs for server- and client-side ad tracking reporting.

    • Example requests for server-side ad-tracking reporting - using URL-encoded pairs




    • Example request for client-side ad-tracking reporting - with no URL-encoding


      POST <master>.m3u8 { "adsParams": { "param1": "value1:", "param2": "value2:" } }


      POST <manifest>.mpd { "adsParams": { "param1": "value1:", "param2": "value2:" } }

For server-side reporting, MediaTailor decodes the parameters when the player request is received. For client-side reporting, it doesn't alter the parameters received in the JSON payload. MediaTailor sends the following request to the ADS:<path>?param1=value1:&param2=value2:

In this way, the param1 and param2 key-value pairs are included as first-class query parameters in the ADS request.